Mechanical locks for railway points are known in the art for preventing a switch rail from creeping away from a stock rail over time, such as if hydraulic pressure drops in a rail-biasing ram. For example, one known actuator arrangement for operating railway points, or track switch gear, on a railway in which a pair of mechanical locks are provided on either side of a pair of hydraulic rams, each ram being arranged to act upon a respective switch rail, for driving that switch rail towards an adjacent stock rail, with the mechanical locks on either side of those rams being locking mechanisms for preventing those switch rails from creeping away from a respective stop rail unless biased away therefrom by an actuation of the opposing ram—the ram for biasing the other switch rail against its respective stock rail.